The common name of this fungus in Chinese, lingzhi, means “herb of spiritual potency” (lingzhi on Wikipedia). It has been used for millenia in Chinese herbal medicine, while Western medicide has yet to satisfy its need for proof about the claims for lingzhi’s efficacy. Efforts to examine the science behind the claims are aptly detailed in both the linked Wikipedia entry and this Fungus of the Month article by Kathleen Engelbrecht and Tom Volk. Do read the Fungus of the Month article for more on this storied fungus.
On the topic of fungi and fungus of the month, January 2007 is the tenth anniversary of Fungus of the Month – if you’ve ever spent some time reading and learning from Fungus of the Month, I suspect it would be well-received if you sent Dr. Volk a note of appreciation (his email address appears on most pages of his site).